Co-authors as letter carriers?
William G. Doty thought that the mention of co-workers as co-authors (at the outset of a Pauline letter) had a two-fold reason: ‘first, he wanted to establish that what he wrote derived not from his own fantasy but from the developing Christian communities; second, the persons mentioned by name were often the trusted persons who were transmitting the letters and whose authority the addressesses were to acknowledge. A very common feature in Hellenistic letters, mention of the carrier established the carrier’s relationship to the writer, and guaranteed that what he had to say in interpreting the letter was authorized by the writer. The feature was especially important in Hellenistic letters where the actual information to be conveyed was trusted (only) to the messenger.’
W.G. Doty, Letters in Primitive Christianity(Guides to Biblical Scholarship; Philadelphia: Fortress, 1973), 30.
This association between co-author and letter carrier seems to me basically wrong. A list of co-authors is: 1 Cor 1.1: Paul and Sosthenes; 2 Cor 1.1: Paul and Timothy; Gal 1.1: Paul and ‘all the brothers with me’; Phil 1.1: Paul and Timothy; Col 1.1: Paul and Timothy; 1 Thess 1.1: Paul, Silvanus and Timothy; 2 Thess 1.1: Paul, Silvanus and Timothy; Phile: Paul and Timothy. For Paul alone as author: Rom 1.1; Eph 1.1; 1 Tim 1.1; 2 Tim 1.1; Tit 1.1. None of these named figures are obviously letter carriers, and others (Phoebe, Rom 16; Epaphroditus, Phil 2; Tychicus, Col 4) clearly seem to be better candidates. Only in the case of Galatians is it likely that one of 'all the brothers with me' may also have carried the letter. (Doty refers to Galatians and may simply have wrongly extrapolated from the rather exceptional Gal 1.1)